A former smuggling route covering both sides of the border has been a “meeting place” for centuries, a cultural heritage expert said.

Brexit negotiators are duelling over the future of areas such as Tyrone and Fermanagh in the North and Donegal in the South, which meet in a remote western peat bogland which no road goes through.

Countryside near Castlederg, Co Tyrone, part of a former smuggling route covering both sides of the border (Michael McHugh/PA)

It once featured in Italian poet Dante’s Inferno about the circles of hell and in more recent years – during the 30-year Troubles – was preserved untouched by human hand because it was not safe, Dr Liam Campbell said.

Its archaeological secrets were built up over 4,500 years in the marshy turf, only stone circles remaining, conifer trees planted on a bare landscape denuded of people.

Dr Campbell added: “It was regarded (by the British) as somewhere the native Irish went to, they were demonised, it was where civilisation ended.”

He said it was known by the settlers as the end of the world.

Dr Campbell said this part of Ireland was famous throughout Europe in the Middle Ages and influenced Dante’s Inferno, after the famous writer read a description of it.

Following the plantation of Ulster in the 17th century, it was known as bandit country, regarded as “dreary” by some English planters in Derry.

A group take part in the Sperrins and Killeter Walking Festival traversing a former smuggling route covering both sides of the Irish border (Sinead Crumlish)

It is the meeting place of three counties, three religious dioceses, three Irish clans, the O’Neills, O’Donnells and Maguires, and a water catchment for the River Foyle.

Dr Campbell added: “This is a real meeting place.

“The whole idea of a meeting place was to provide sanctuary.”

In the old Irish, place names were based on what people could see, maps were memorised using local landmarks.

A group as part of the Sperrins and Killeter Walking Festival and organised by adventure company Far and Wild traversed the difficult terrain.

Dr Campbell added: “We are talking about the idea of being in-between places and it is no accident that we are near Lough Derg (the Catholic pilgrimage site).

“This actually was not the end of the world, it was the centre of the world in many ways.”

It is one of the most far-flung areas of the Irish border, the most vexed issue remaining facing Brexit negotiators.

Walkers near Castlederg, Co Tyrone (Michael McHugh/PA)

Once grouse were hunted on its broad moorlands. Nowadays it is entirely depopulated.

A few ruined houses, overgrown with moss, “knapped” or hewn from the limestone which characterises this area, by hand and with intricate decorations.

The area was associated with the blacksmith.

Lorcan McBride, who led the walking group, said: “The blacksmith was the priest before the priest, they dealt with elements like fire and water, the blacksmith had the key to the other world.

“This area was a meeting place.”

The last resident, Packie McGrath, left in 2016.

He was an only child, used well water and had no road access.

Mr McBride said: “It was 1950s conditions, gas stove, no electric, living on his own with the birds and the bees.”

Nearby lay the ruins of a post-Irish famine house, perhaps built in the 1860s and made mainly from limestone.